If everybody had a large, blank, white wall behind their TV, with their TV mounted on that wall, illumiroom could possibly MAYBE be something. But for people who live in cramped homes, and/or maybe have oddly colored wallpaper along with picture frames and stuff, bookshelves or maybe even windows, it just wouldn't work properly.
Illumiroom looks like something tailor-made for upper middle-class or better people living in US-style single-family homes. Most of the worild isn't like that. It's also an anchor on performance, putting additional drag on an already weakish GPU.
I certainly hope this gadget never becomes a retail product, because it's just a bloody gimmick. Other than that I'm really stoked for this conference, it's been eight friggin years since last MS reveal and it feels like it as well. Holy crud. Teen gamers of today were in junior grade school back then, if they were in school at all!
My mate's oldest kid was busy being born around the time when the 360 was revealed...